1. Field
This disclosure relates generally to voltage multipliers, and more specifically, to variable load, variable output charge-based voltage multipliers.
2. Related Art
Traditional voltage multipliers suffer from several drawbacks. For example, traditional voltage multipliers are limited to a narrow range of output voltages and loads. This is because a voltage multiplier is typically required to satisfy certain performance requirements. Traditional voltage multipliers when used to obtain a broader range of output voltages and loads fail to meet these performance requirements. One of the performance requirements for a voltage multiplier relates to a ripple factor that the output of the voltage multiplier needs to satisfy. Traditional voltage multipliers stop the clock when the output voltage is greater than the regulation voltage and then depend on the load to depress the output voltage. This method of generating a regulated voltage suffers from excessive ripple.
Additionally, in traditional voltage multipliers, the ripple present in the output of the voltage multiplier can vary based on the output voltage that the voltage multiplier is required to supply. This is because to vary the output voltage, typically, a multi-stage voltage multiplier is used in which the number of stages can be varied to change the output voltage. However, if the number of stages is increased to accommodate the load, the ripple also increases.
Accordingly, there is a need for charge-based voltage multipliers that can handle variable load and provide various output voltages without a concomitant increase in the ripple.